ASP Service quick start (.NET 5.0)

/*
  ASP.NET Base for service
  .ASP.NET 5.0
  Author - aws (qwark)
*/

using Microsoft.AspNetCore;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Text.Json;
using System.Text.Json.Serialization;

string ToJson(object obj)
{
    return JsonSerializer.Serialize(obj);
}

WebHost.CreateDefaultBuilder()
    .Configure(x =>
    {
        x.Map("/api", z => z.Run((context) =>
        {
            return context.Response.WriteAsync($"Hello. Its root page of service\n" +
                $"Request query: {ToJson(context.Request.Query)}\n");
        }));
        x.Map("", z => z.Run((context) =>
        {
            return context.Response.WriteAsync("aws service\nUse /api for more info...");
        }));
    })
    .UseUrls("http://localhost:1010")
    .Build().Run();